Thursday, January 31, 2013

Scientific Journal Article search engines

Plants at Como Conservatory - N. Carlson

Google has a new search feature called Google Scholar.  It can be used to search journal articles or legal documents.

Scirus - for Scientific Information Only.

Pub Med - Biomedical Journal articles - from NIH

IEEE Xplore - Searching for technology information.


Wednesday, January 30, 2013

US Bird Deaths: Cats vs Wind turbines

According to the US Fish and Wildlife Services as reported in Scientific American: wind turbines account for approximately 1/2 million bird deaths annually in the United States.  In a recent Nature article as reported by the BBC, cats (primarily stray and feral) were estimated to kill between 1.4 and 3.7 billion birds annually in the United States.  According to the US Humane Society there are an estimated 50 million feral cats in the US compared to 86.4 million domestic cats.

Not this kind of cat.  Smaller cats - National Zoo - N. Carlson

According to, buildings are estimated to kill 1 billion birds per year.  A bird safe building guideline is available from the Audubon Society of Minnesota.

In summary, wind turbines are conservatively 1,000 times less effective at killing birds than other buildings or the birds feline foes.  Sylvester is doing very well in his quest for a tweety bird although his homeless cousin does more damage. 

Tweety and Sylvester - Warner Bros.

Bob Barker and Drew Carey may be on to something.

Friday, January 18, 2013

Wallemia spp.

The organism, Wallemia spp. prefers to grow in conditions with higher sugar content than most fungal organisms.  It grows well on straw and on carpet adjacent to pop machines where there may have been liquid spills.  It grows well on DG-18 media at 25 degrees Celsius and not very well on MEA or PDA. 

Wallemia spp. on an Air-O-Cell cassette sample  - N. Carlson
If there are several spores in a chain it can be identified with care on an Air-O-Cell cassette sample. 
Each individual spore is typically less than 3 microns in length.

Wallemia spp. 400x from culture - N. Carlson
Wallemia spp. single colony growing on DG-18 - Photo N. Carlson 

Wallemia spp. growing on DG-18 - N. Carlson

Stemphylium spp.

The leaf decay fungi, Stemphylium spp. grows well on PDA and MEA.  It can be recognized on an Air-O-Cell cassette air sample if there is a mature spore.   The mature Stemphylium spp. spore has a transverse septation that divides the top and the bottom of the spore similar to the waist on a human.  Immature spores can be confused with Ulocladium spp.

The organism grows on decaying leaves and has a preference for tomato plants. Pleospora spp. is the teleomorph (sexual stage) of this organism.

Line drawing of Stemphylium spp. N. Carlson
Stemphylium spp. with acid fuschin stain 400x N. Carlson

Stemphylium spp. with 85% lactic acid stain 400x - N. Carlson

Thursday, January 17, 2013

Antioxidant supplements: Friend or Foe?

I've summarized a few articles over the past few years that question the theory that antioxidant supplements have a salutary effect on health and cancer.

Why those antioxidants may be causing more harm than good.  by Brian Clegg of the  He notes that the boring activities of maintaining a proper weight, refraining from smoking and excessive drinking, exercising have been shown to work.  Antioxidant supplements can not be treated as a magic bullet.

Vitamin pills can lead you to take health risks - Ben Goldacre - UK Gardian.  People who thought they took a vitamin pill smoked more than those who were told they took a placebo.

James D. Watson Reuters AP photo

Nobel laureate warns against antioxidant supplements -  by Susan Perry at MinnPost.  James D. Watson offered a scathing critique of current cancer research and of the problems with the use of antioxidant supplements. At least in the lab antioxidants appear to give cancer cells a better chance of survival.

Since I have been consuming antioxidant cereal and taken a male multivitamin with selenium I was a bit surprised by the research and the opinion of Mr. Watson.  I shouldn't be in retrospect as the Greek maxim of everything in moderation appears to be a good general guide to life.

The controversy over the effectiveness of antioxidants will be worth watching. 

Tuesday, January 15, 2013

Take online survey on home IAQ to help researchers at LBNL

Researchers at the Lawrence Berkeley National Laboratory are conducting a survey into household cooking activity and its possible effect on residential indoor air quality.

Click on Household cooking survey to take part.

Tuesday, January 8, 2013

Harnessing power from osmotic energy
Norway pilot plant produces electric power from the osmotic energy produced when fresh and salt water are separated by a membrane. 

National Geographic notes the Pressure Retarded Osmosis (PRO) method is expensive and will need to have a significant reduction in the cost of membranes to be cost effective.  They plan on combining the PRO method with a tertiary treatment (PRO/TT) to generate energy while purifying water.
Researchers in the Netherlands are working on a reverse electrodialysis RED method, which uses the difference between salt and fresh water to create a direct current battery.   Other researchers have combined RED with microbial fuel cells (MFC) to produce electricity.  The combination is called a microbial reverse electrodialysis Cell (MRC).  It reduces the surface material for membranes and increases the electrical production from the cells.

Bruce Logan - Penn State

Monday, January 7, 2013

Boxelder seeds found to cause disease in horses

Researcher at the U of Minnesota Veterinary Medical Clinic have found a link between toxins in boxelder seeds and seasonal pasture myopathy in horses.   In areas where other vegetation is sparse and hay is not given in adequate amounts, horses will eat the boxelder seeds and become ill.  The symptoms are awkward gate, dark colored urine and difficulty breathing.  The case fatality rate is 90%.  The article, Seeds from tree trigger devastating disease, was published in

The boxelder photos below are from

Boxelder leaf - Member of the maple family

Boxelder seeds 

Aspergillus ochraceous

The fungal organism Aspergillus ochraceous has popped up in several odd places during indoor air investigations.  I have found it in steam tunnels, near potted plants and on carpet.  The organism is capable of producing ochratoxin.

The organism can be  confused with Aspergillus flavus because of the the rough stipe.  But the yellow colony color and the uniformly biseriate head help differentiate this species.  It grows well at 25 degrees Celsius

The organism has no specific identifying characteristics on an Air-O-Cell cassette.  It would be classified as Asp/Pen like.

Aspergillus ochraceous growing in culture - N. Carlson

Stereo microscope photo of Aspergillus ochraceous 100x - N. Carlson

Aspergillus ochraceous 400x. - acid fuschin stain - N. Carlson

What are mycotoxins - 3 min.